CVSS 4.0
5.3 mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NCVE-2026-119425
OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.
Severity
CVSS 3.1
5.4 mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N- CWE
- CWE-290
- Published
- Modified
- Record from
- the NVD, synced
References
- https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam
- https://github.com/opnsense/core
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78
- https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834
- https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55